The invention relates to short-range data communication.
Radio frequency identification (RFID) systems, for example, typically include a reader or interrogator, a transponder and a data processor. The reader may include an internal microcontroller, a transmitter, a receiver, and an antenna. The transponder is usually a passive device (having no power source) embedded in a card or key tag, and may include an antenna and a RFID application specific integrated circuit (ASIC). The interrogator transmits an electromagnetic wave defining a surveillance zone. When a transponder enters the zone, the electromagnetic energy from the interrogator begins to energize the ASIC in the transponder, which initializes and then broadcasts an identity signal.
A RFID system may use a low-energy, back-scattering technology that selectively reflects or back-scatters the electromagnetic energy from the transponder back to the interrogator. Receiving circuitry in the interrogator senses and decodes the back-scattered signal to determine the identity of the transponder. Such a system may be used to identify, track and/or locate people or objects.
In a typical application, when an acceptable identity signal has been received, an interrogator generates a signal to unlock a door for entry of the carrier of a key tag transponder. Another application uses button transponders attached to an article of clothing to communicate with an interrogator in a washing machine or the like. The button transponders communicate data to the interrogator that are used to alter the water temperature and/or the cleaning cycle for the clothing.
RFID systems typically offer a single communication path between a reader and the transponders, and have short read ranges between the interrogator and a transponder, which may be measured in centimeters. Greater ranges, very often the goal of RFID systems, require use of higher power levels and/or increased antenna size, and produce less confined radio frequency fields.
Presented is a method, from an interrogator held near a person, of interrogating multiple transponders in the vicinity of the person. As a result of the interrogating, information is received separately from the multiple transponders.
The method may include one or more of the following features. The interrogator may be held in an article of clothing or personal effect of the person. The articles of clothing or personal effects may include at least one of pants, shirts, jackets, coats, earphones, glasses, listening devices, necklaces, rings, watches, bracelets, walking sticks, hockey sticks, guns, cups, and other fashion and everyday accessories and items, hats, socks, shoes, ties, underwear, outerwear, pens, pencils, personal digital assistant devices, laptop computers, desktop computers, bags, backpacks, luggage, wallets, money clips, timepieces, wristwatches, cell phones, desk phones, pedometers, temperature sensors, global positioning devices, environmental sensors, biological sensors whether worn on the garments or below the epidermal skin layer of the human body or embedded or mobile within the human body, fitness devices and other appliances and equipment. The transponders may be associated with respective articles of clothing and personal effects of the person, and the information received from the multiple transponders may include identifying information or information associated with states of articles of clothing or personal effects of the person or sensor readings of the environment or of the person. In addition an activation signal may be transmitted from at least one of the transponders, that could be used to activate another device or transponder to perform a function such as transmit data, start an actuator or display information.
In another implementation, a method includes radiating an interrogation field over less than a predetermined distance from a radiator. Then from at least one position within the predetermined distance, carrying energy associated with the interrogation field along at least one respective conductive element to at least a first location that is farther than the predetermined distance from the radiator, and at each location, radiating an interrogation field using energy that has been carried along the conductive element.
This implementation may include at least one or more of the following features. The radiator may be an interrogator. The interrogation field may be a radio frequency field. A transponder may be located within a predetermined second distance of at least one location. The conductive elements may be electrical conductors. The method may include deriving the energy carried along the conductive elements inductively from the interrogation field. The method may also include, from a position that is within a predetermined second distance from at least the first location, carrying energy associated with the interrogation field along at least one additional pair of conductive elements to at least a third location. At least two respective conductive elements may also carry modulations of the interrogation field from the first and second locations to the positions that are within the predetermined distance of the radiator.
In yet another implementation, a short-range communication system includes an interrogator, a network of coupling ports, communication lines connecting the coupling ports to the interrogator, and at least one transponder associated with an object. The transponder may establish communications with at least one of the coupling ports and the interrogator.
The communication system may include one or more of the following features. The interrogator may include a microcontroller that transmits at least one interrogation signal to initiate communications. An output device may be connected to the interrogator. An input device may be connected to the interrogator. The interrogator may include a switch for initiating and terminating interrogation signals, and the interrogator may include a receiver to receive signals from each of the transponders. At least one of the transponders may be configured to send an activation signal. The system may include electronic circuitry to increase the sensitivity of the coupling ports.
In a further implementation, a short-range communication method includes creating a network of coupling ports in a material, connecting an interrogator to the network, and activating the coupling ports to interrogate at least one transponder.
Implementations of the short-range communication method may include one or more of the following features. The interrogator may generate interrogation signals in a status reporting mode to determine which transponders are within range of the coupling ports. The interrogation signals may be transmitted along a predetermined or assigned set of communication lines and associated coupling ports in a sequential or broadcast manner. An anti-collision protocol may be used if at least two transponders respond to the same interrogation signal. The interrogator may generate interrogation signals in a locating mode to locate the transponders in the network, and the interrogator signals may be transmitted along a predetermined or assigned set of communication lines and associated coupling ports in a sequential or broadcast manner. In locating mode, an anti-collision protocol may be used if at least two transponders respond to the same interrogation signal. The interrogator may also generate interrogation signals in a position mode to determine the position of a particular type of transponder, and the interrogation signals may be transmitted along a predetermined or assigned set of communication lines and associated coupling ports in a sequential or broadcast manner.
A communications system according to the invention can advantageously be used in a wide variety of applications. For example, an implementation of the invention enables clothes worn by a person to communicate with a plurality of items and obtain useful information. In addition, a network system according to the invention may be configured so that transponders may communicate with other transponders or devices to activate functions, cause actions or otherwise share data and/or information. Other advantages and features will become apparent from the following description and from the claims.